As a semi-professional web designer, I highly recommend Dreamweaver (versions 2.0 and beyond).
Frontpage is a decent program, but is not as flexible or powerful. In addition, it introduces redundant code (As someone else already mentioned). It's much harder to create a clean code using Frontpage, so it's therefore more difficult to try and learn the code through modification under "Source" mode.
Frontpage is more of a WYSIWYG editor for beginners, in my opinion. Dreamweaver allows for both. It's quite easy to use, and allows the user to edit the code without too much hassle due to redundant coding.
You have you ask yourself what you need it for and how much you are willing to pay for the program. If money was not an issue, I would go with Dreamweaver no questions asked. It's simply more powerful and flexible, yet simple to use.